Method of making rosin size



Oct. 10, 1933. .1. A. DE CEW METHOD OF MAKING ROSIN SIZE Filed July 10, 1929 ATTORNEY Patented 0a., 10, 1933 g p 1 929;577 LIMETHODQOEIMAKINVG nosm sizri 1 Jimsommne Gew}Mount vernon'g N. Ytpas'signor j 1 to Process Engineers,

: corporation ?of NewiYork 1 1110.; New. York; NrYy, a

, Application July 1929., Serial No. 377,309 h 1 3 Claims.

. The universal method'ior making rosin-size for paper mills is to"boil:the rosin .in a-solution of sodium carbonate-until avlarge; portion ofthe rosinacids are, formed intoa rosin. soap and the alkali ispracticallyzneutralized and thecarbonic acid has been driven off in the "boiling process; If this. size 18 11101.; soluble in cold water,

.it'is generally-dissolved by :the. use of some a special emulsifying device'by means ofi'whieh sit is put into-dilute solution=inwater. -:Attempts have been made tosaponify rosin by boiling it in a strong solution-of caustic'sodav-or potash, but when this is done the saponification generally results'in ahydrolysis ofthe rosin soapso that it forms a gell like mass that is so .stifi and viscous that it cannot be-used.to-advantage.

A gelled size having a Waterconte-nt of :40 or of water cannot be melted for packaging in {drums and cannot be zemulsified by the; or-

dinaryprocesses. v p I V A=rosin size made with rosin andxcaustic'rsoda has certain advantages; a-however, owing to the solubility, and owingj to the fact that such a size has, more. stability than: one. madeqwith wsodium carbonate. a

Methods have been des rosin has been partiallysaponified with a cold dilute solution, of caustic soda circulated; over lumps of rosin; andzin thisway the extreme reactions resulting from. boiling withthe caustic soda" areavoided. Without-heating, however, suchreactions are not/complete. Y

I have invented a newp'rocess of saponification which 'does-not ;boil this rosin..inthe caustic-alkali non-does it require the expensive installation or theflength rot -time used; in cold .s aponification. In fact; I find that the -best temperatures forc'saponifying this'alkali are below the boiling point and that the saponification should take jplacezin a more dilute solution, the best concentration being between 4% and 10% rosin to the amount of water used. The principle of my process is that 'I first emulsify the rosin and then saponify it. The first function of the alkali is to act as an emulsifier, and the second step is to combine with the rosin acids.

It is much easier to saponify'in emulsion of rosin than it is. a solid rosin. I now describe this process as follows in connection with the accompanying drawing in which the figure shows in conventional manner apparatus suitable for carrying out the process.

I first melt the rosin in any suitable container using either. a jacketed tank 1, the jacket of whichmay be replaced by steam coils or other cribed "inmwhich :the

-heati ngq'medium. The melted rosinsis then aln lowed tto flow: through an. emulsifying apparatus injector: Z preferabIy suchas .showniin my ;P atent,-. 1,522,371, January 13; -.1925;:.in which it comes into. con-tactvwitm a solutionof, caustic;

alkali supplied to the injector by pump; 3:.suppliedqby. :pipes. 45 from? any suitable; source :(not Ishown) which. :in'j eCtOI v serves as wan a'git'ating means:- whereby the rosin-and caustic: alkali-are thoroughly agitated and Icommi-ngled and the i shot-caustic solution andthewemulsion is forced into/a istoragemanki 5.:thr0llghz PiPQ fi. This emulsion may be heated in the storage-,tank -jby cmeanszasucmas steamr'gcoil; 7;"10r-if" hot enou h,

-.is. iallowedctozstandtuntil the :free zcausticz in the aem-ulsionahas reactedxwith :the iro'sin acids: inithe i'emuls'ion after. which. it; may be cooledby further radilutionxo Theltime.necessarytforthis saponifia cation will'Fderpend upon:the?concentrationand temperaturejotthe zemnls'ioriaaanditheszcomplcteness of the saponification desired; my: this method, I-canimake: arosin 'isizeiwith any desired percentage "of free rosinifrom l5% of the total-rosin;.to' of the t'ota'l'rosin. The A character of the size made can bef controlled 1 within these limits byvar'ying' thewamountiaof "caustic alkali used and by controlling .th'ei concentration and temperature: of theemulsion. .Jf;

5 there is any 1 jelling *of the size after saponifi- *cationf-this will not reduce the-fluidity su fil- =der10%' solids. After the=-size-hasreaehedthe required amount of saporii-fication; it may-be further 'diluted'to a flconoehtratiom bf 1* or" 2% solids-bythe'= addition-' -"of cold -water, :through water supply pipe 8. 1

free alkali in the emulsionto a minimum and it is not desirable. to have over 1 or 2% of free alkali inthe sizing emulsions. Onthe one hand,

ciently to affect the emulsions" for the saponifi "cation-will take place in a concentration of un-:

This process has an advantage over cold saponification as it makes it possible to reduce the the rosin'canbe saponifiedwithout boiling and consequently a lighter colored solution can be made than would be made by using caustic soda at boiling temperatures. i v V It is not necessary in the operation of this process to add anything to the rosin in order to emulsify it with. the caustic alkali, although; I may add such ingredients as oils, fats or waxes,

alps

in order to modify the character of the finished product. I can make by this method either sizing emulsions or sizing solutions.

When sizing emulsions are desired, the amount of alkali used is less than that required to combine with the rosin acids present. When sizing solutions are desired, the amount of alkali is used which when combined with rosin acids,

.will dissolve all of the particles of rosin in suspension.

If a compound is used which consists of an unsaponified wax and rosin acids, then the rosin acts as an emulsifying material with the alkali and produces a wax emulsion, and the free alkali by continuous reaction with the free rosin acids maintains by saponification the stability of the emulsion. V, I

This illustration 'is given to show the wide application of this process. Its difference from other processesis the fact that instead of saponifying apart of the rosin before emulsification or dissolving emulsifying agents in the rosin composition, the product is first emulsified by mechanical and chemical means and then when desired a saponiflcation is brought about in the emulsion.

' The caustic soda which I have described in this process may be replaced by either caustic potash, caustic ammonia, or silicate of soda...

An alkaline. carbonate might be used instead of caustic but this-does not react as rapidly as a caustic alkali and requires higher temperatures ,and it would produce a frothing action in the saponification-tanks. Sodium carbonate may be used for the emulsifying action and caustic alkali-added to-the emulsion to produce sapon- The outstanding features of this process are that first the rosin is broken up into fine particles by the emulsions process and these particles stay in suspensionso that saponification may take place quickly in the dilute solution with the application of heat because all of the fine'particles are attacked at once and no agitation is necessary. v d v The size produced in this way is'different from any other kind of size because in all other methods the .saponification is progressive;

When. rosin size is made in a concentrated solution, as is the general practice, so thatthe finished size'will have from 50 to 30% of water,

then the action takes place as follows: First a portion of the rosin is saponified and then the rest of the rosin dissolved in the concentrated soap, and is saponified later. It is a mixture in which some of the rosin has been saponified a much longer. time than the rest. 0ver saponificationproduces coloring matter in the size.

If rosin is saponified by circulating cold caustic over some lumps then this saponification will also be progressive. My method of saponifying produces simultaneous reactions; first, the emulsified rosin is uniform and second, the saponified product is also uniform.

For special purposes, I may stop the process at the stage of emulsification and not add furtherheat than that already in'the hot water in which case, I will have a small amount of rosin soap and mostly free rosin and some free alkali.

It is possible to operate this process by first emulsifying theprosin with a small amount of alkali and then add the caustic to the emulsion tank and saponify the rosin in the emulsion.

In my process I as described in Patent No. 1,317,616, of September 30, 1919, I add alkali to free rosin emulsions, but the purpose of this isto stabilize'the' emulsions, and the emulsions are cooled instead of being heated so that saponrosin, and thereafter treating the said emulsion separately in a container without dilution at a temperature below the boiling temperature of the emulsion and under conditions favorable for saponification ofrosin to produce a lighter colored product than that obtained by boiling the emulsion. 1

2. A process of preparing rosin size which consists in melting rosin, thoroughly agitating and commingling melted rosin with a dilute alkali solution to form an emulsion at a concentration ofunder 10% solids under conditions unfavorable for saponification of rosin, and

thereafter heating the resulting emulsion before dilutionof the said emulsion at a temperature below the boiling point of the emulsion to bring about rapid and uniform saponification of rosin with alkali in the emulsion.

3; A process of preparing rosin size whichcon sists in melting rosin, thoroughly agitating and commingling melted rosin with-a dilute alkali solution to form an emulsion under conditions unfavorable for saponiflcation of rosin, and thereafter heating the resulting emulsion at. a temperature below the boiling point of the emulsionto bring about rapid and uniform saponiflcation of rosin withalkali in the emulsion.

JUDSON' A. DE CEW. 

